Sea Saliva in the Sea of Marmara

Sea saliva is a collection of a slippery, aqueous organic substance found in the seas and oceans, especially in those which are relatively still and have a shallow depth. The viruses and bacteria can easily get attracted to the substance, forming a blanket that suffocates the marine life below.  It is formed as a result of prolonged warm temperatures in areas with abundant nutrients in the water and with the increasing rates of global warming it is a fact that it will be spread out to the whole world in a short amount of time. In addition to the increased temperatures, direct waste or wastewater dumped into seawater is also a factor affecting the accumulation of sea saliva. The components of wastes lead to the proliferation of phytoplankton. These microscopic organisms usually help fill the ocean waters with oxygen, but when accumulated they become stressed and grow out of control. As a result, they produce a sticky substance that can span many square kilometers.

Accumulated sea saliva was first spotted in the Mediterranean sea in the early 18th century, and it has also been a problem around the Aegean and Black Seas. In 2010, the Deepwater Horizon Oil Spill1 in the Gulf of Mexico created large amounts of sea saliva to form as a result of the massive killing of microscopic organisms in the area. Sea saliva has even been observed under the ice in the Alps and the Antarctic, along with some rivers and lakes. For the past few weeks, the Marmara Sea around Turkey has been dealing with the huge spread of saliva all over the coasts. Although, it is a longstanding problem in Turkey approximately since 2007, now is the highest extent to which the sea has been covered with a white layer. 

The Change in Sea Temperature in Marmara

Many researchers explain the sudden accumulation and appearance of sea saliva with the increasing pollution and temperatures. It is known that the temperature of the Marmara Sea has increased up to 2.5 degrees over the past 20 years and the wastes from agriculture, industrial runoff, or sewage have been weakening the ecosystem and biodiversity. According to the research done by the Institute of Marine Sciences at METU2, the saliva has been spread up to 80 to 100 meters below sea level and as far down as the seabed. As the sludge continues to spread and sink beneath the surface, it sucks up oxygen in the water and threatens the diverse ecosystem of the region hosting mussels, crabs, clams, corals, around 230 species of fish, and sometimes even dolphins. The sea snot increasingly weighing down will also risk the highly important fishing industry by snapping their nets and most importantly killing their income sources. Furthermore, in the case of saliva triggering the production of E.coli bacteria3, which presumably will happen if continues at this rate, people swimming in the gloopy water will be at risk of death. This will be another calamitous tragedy for the tourism industry in Turkey that is already struggling with the COVID-19 pandemic since the beaches will definitely be closed. 

In the past week, the Ministry of Environment of Turkey has collaborated with several research institutes to get samples from the sea saliva and find a way to eradicate it from the Marmara Sea. These research faculties are now examining the sample water with sea saliva in terms of its oxygen content, saltiness, temperature, pH, light transparency, and clarity. 

“According to our scientists, if we reduce the amount of nitrogen by 40%, we’ll have solved the root of this problem. We will take all the necessary steps within three years and come up with projects that will save not only the present but also the future together.”

– Murat Kurum, the Minister of Environment and Urbanization of Turkey

After they came to the conclusion that the oxygen levels around the regions with sea saliva are critically less than the other regions, the Ministry has initiated the ‘Marmara Sea Protection Action Plan’. Under this plan, they have published a 22-point action list to tackle the sea snot and clean up pollution in the Marmara:

  1. A Coordination Board composed of the Ministry of Environment and Urbanization, relevant institutions and organizations, universities, chambers of industry, and NGOs will be formed along with a Science and Technical Board within the body of Marmara Municipalities Union.
  2. The Marmara Sea Integrated Strategic Plan will be prepared within three months and the needed work will be carried out within the framework of this plan.
  3. Necessary actions to designate the entire Sea of Marmara as a protected area will be initiated and completed by the end of 2021.
  4. As a part of the emergency response, as of June 8, 2021, studies will be initiated to completely clean the mucilage in the Sea of ​​Marmara with scientific-based methods.
  5. All of the existing wastewater treatment plants in the region will be converted into advanced biological treatment plants. Studies will be carried out in line with the objectives of preventing the discharge of wastewater into the Marmara Sea without advanced biological treatment.
  6. The discharge standards of wastewater treatment plants discharging into the Marmara Sea will be updated and implemented within 3 months.
  7. The reuse of treated wastewater will be increased and supported wherever possible. Clean production techniques will be applied.
  8. The transition to advanced treatment technologies will be accelerated by rehabilitation and improvement works of organized industrial zones that do not operate wastewater treatment plants as they should.
  9. Public-private partnership models will be implemented to make the construction and operation of wastewater treatment plants much easier.
  10. The regulation to prevent the discharge of wastewater from ships into the Sea of ​​Marmara will be made within three months.
  11. Cleaner production techniques will be expanded in the shipyards.
  12. Within the framework of the studies carried out by the Ministry of Environment and Urbanization; All wastewater treatment plants that discharge to the receiving environment will be monitored online. 91 monitoring points in the Marmara Sea will be increased to 150. With the help of the Turkish Environment Agency, inspections in all basins associated with the Marmara Sea will be increased by using remote sensing, satellite and early warning systems, unmanned aerial vehicles, and radar systems.
  13. The Regional Waste Management Action Plan and Marine Litter Action Plan, covering the coasts of the Marmara Sea, will be prepared and put into practice within three months.
  14. Good agricultural and organic farming practices and pressure and drip irrigation systems will be expanded.
  15. In the basins associated with the Marmara Sea, artificial wetlands and buffer zones will be created on the stream beds, thereby preventing the pollution from reaching the sea.
  16. In order to prevent pollution originating from olive black water and whey, technological transformations will be provided to reduce wastewater.
  17. The use of cleaning materials containing phosphorus and surfactants will be gradually reduced.
  18. All ghost nets in the Sea of ​​Marmara will be cleared within 1 year.
  19. It will be ensured that fisheries activities are carried out on an ecosystem basis, and protected areas will be developed.
  20. Financial support will be provided to fishermen who have suffered damage due to mucilage.
  21. A platform will be created to inform the public in order to prevent marine pollution and to raise awareness of our citizens.
  22. Measures will be taken to reduce the effects of hot waters consisting of cooling waters and thermal facilities on the Marmara Sea.

“The implementation plan that the minister has presented is a very good start. If the measures are introduced quickly, oxygen levels will begin to rise and the situation will start improving within months. The sea will never recover it to its original pristine state, but its resilience hopefully will increase.”

– Barış Salihoğlu, Head of METU’s Institute of Maritime Sciences

Considering the high population density and economic activities of the Marmara Region, it will definitely take more time than expected to assimilate the facilities and public to the new measures. However, the ecosystem should always be considered as the first priority and no single concession should be made. The plan should be implemented as quickly as possible to reduce the nutrient loads in a short period of time, at least enough to decrease nitrogen density by 40%. Hopefully, by the end of 2021, sea saliva can at least be decreased to a non-critical level and the ecosystem will repair itself.

1  Deepwater Horizon Oil Spill is caused by an explosion on April 20, 2010, at an oil rig located in the Gulf of Mexico.

2 Middle East Technical University

3 E.coli, abbreviation for escherichia coli, is a gram-negative, facultatively anaerobic, rod-shaped bacteria that can be deadly for organisms when produced in high amounts.


“Sea Snot.” Wikipedia, Wikimedia Foundation, 8 June 2021, 

“Marmara Denizi Koruma Eylem Planı.” Marmamara Denizi Koruma Eylem Planı, 2021, 

“EYLEM PLANI.” Marmara Hepimizin!, 2021, 

(, Deutsche Welle. “Turkey’s ‘Sea Snot’ Is Part of a Growing Environmental Threat: DW: 08.06.2021.” DW.COM, 2021, 

“Sea Saliva Threatens Underwater Life off Istanbul.” Hürriyet Daily News, 2021, 

Azbay, Şengül, and Kadir Yıldız. “’Mucilage Warning System for Marmara Sea Is Needed’.” Anadolu Ajansı, 2021, 

Pallardy, Richard. “Deepwater Horizon Oil Spill.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 13 Apr. 2021, 

“Escherichia Coli.” Wikipedia, Wikimedia Foundation, 7 June 2021,

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